Aorta cross clamp assembly

ABSTRACT

An aorta cross clamp assembly includes a clamp having movable jaws and a removable actuator having movable handles. Initially, the actuator is connected to the clamp with the jaws in an open position. When the actuator handles are closed, the jaws also will be closed. The clamp is provided with a toothed retainer that prevents the jaws from being opened accidently. The actuator can be detached from the clamp and removed from the operative site, leaving the locked clamp in place. When it is desired to remove the clamp, the actuator can be reattached to the clamp and used to disengage the toothed retainer. The actuator then can be used to spread the jaws in order to permit the clamp to be removed. The clamp and the actuator are provided in two forms. In one form, the toothed retainer is engaged and disengaged by movement toward and away from the jaws (“horizontal” movement). In the other form, the toothed retainer is engaged and disengaged by movement generally perpendicular to the jaws (“vertical” movement). Another embodiment employs a clamp having movable jaws and a slender, flexible, actuator that is not intended to be removed during use. The jaws are actuated by axial movement of a screw that is connected to the end of a cable included as part of the actuator. The screw passes through a slotted nut that permits non-rotational axial movement of the screw in one direction to close the jaws, but which requires that the screw be rotated in order to move in the opposite direction to open the jaws.

REFERENCE TO PENDING APPLICATION

[0001] The present application claims priority from, and incorporates byreference, provisional application Ser. No. 60/181,435, filed Feb. 10,2000 by Albert N. Santilli.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The invention relates to clamps for surgical procedures and, morespecifically, to a clamp assembly especially useful for clamping theascending aorta during cardiac surgery.

[0004] 2. Description of the Prior Art

[0005] During the course of cardiac surgery in which cardiac function isarrested, it is necessary to isolate the heart and coronary bloodvessels from the remainder of the circulatory system. Circulatoryisolation of the heart and coronary blood vessels is usuallyaccomplished by placing a mechanical cross clamp externally on theascending aorta downstream of the ostia of the coronary arteries, butupstream of the brachiocephalic artery so that oxygenated blood from thecardiopulmonary bypass system reaches the arms, neck, head, andremainder of the body. Using conventional techniques, the sternum is cutlongitudinally (a median sternotomy) thereby providing access betweenopposing halves of the anterior portion of the rib cage to the heart andother thoracic vessels and organs. Alternatively, a lateral thoracotomyis formed, wherein a large incision is made between two ribs and theribs are retracted. A portion of one or more ribs may be permanentlyremoved to optimize access.

[0006] Regardless of whether a sternotomy or a thoracotomy is performed(both collectively referred to herein as a “gross thoracotomy”), theopening in the chest wall must be large enough to permit a cross clampto be placed externally on the ascending aorta, thereby isolating theheart and coronary arteries from the remainder of the arterial system. Aproblem with existing cross clamps is their excessive size. A crossclamp usually includes a clamping portion from which integral actuatinghandles project. The clamp occupies a relatively large portion of theoperative site, thereby requiring that the sternum or ribs be retractedto a greater extent than is desired. This is a significant factor inopen-chest surgery, because the trauma caused by creating large openingsin the chest wall often entails weeks of hospitalization and months ofrecuperation time.

[0007] Recently, techniques have been developed to facilitate theperformance of cardiac procedures such as heart valve repair andreplacement, coronary artery bypass grafting, and the like, usingminimally invasive techniques that eliminate the need for a grossthoracotomy. Coronary artery bypass grafting, heart valve repair andreplacement, and other procedures can be performed through smallincisions or cannulae positioned in the chest wall. In one recentlydeveloped technique, a clamp is introduced into the patient's thoraciccavity through a percutaneous intercostal penetration in the patient'schest, typically using a trocar sleeve. The clamp is detachably mountedto the distal end of a clamp positioner. After the clamp is positionedaround the ascending aorta, the clamp is actuated from outside thepatient's thoracic cavity to squeeze the aorta and partially orcompletely block fluid flow therethrough. The clamp then is disengagedfrom the distal end of the clamp positioner and the clamp positioner isremoved from the thoracic cavity to provide enhanced access to theregion in question.

[0008] Although the referenced device permits cardiac surgery to beconducted with significantly smaller openings formed in the chest wall,there is a concern about the reliability of the clamp and whether aconnection can be reestablished between the clamp and the clamppositioner when it is necessary to remove the clamp. A failure of theclamp or the inability to remove the clamp could have disastrousconsequences for the patient.

[0009] Despite the advantages of minimally invasive cardiac surgery,certain situations still call for the use of a gross thoracotomy. Insuch circumstances, there remains a need for an aorta cross clamp thatis smaller than existing cross clamps but which is extremely reliableand easy to use. In those cases where minimally invasive surgery isindicated, there is a need for an aorta cross clamp that is easy toapply to the ascending aorta, which is reliable in use, and which can beremoved without fail.

SUMMARY OF THE INVENTION

[0010] In response to the foregoing concerns, the present inventionprovides a new and improved aorta cross clamp assembly. In oneembodiment especially suited for use during a gross thoracotomy, a clamphaving movable jaws is provided with a removable actuator having movablehandles. Initially, the actuator is connected to the clamp with the jawsin an open position. When the actuator handles are closed, the jaws alsowill be closed. The clamp is provided with a toothed retainer thatprevents the jaws from being opened accidently. The actuator can bedetached from the clamp and removed from the operative site, leaving thelocked clamp in place. When it is desired to remove the clamp, theactuator can be reattached to the clamp and used to disengage thetoothed retainer. The actuator then can be used to spread the jaws inorder to permit the clamp to be removed.

[0011] The clamp and the actuator are provided in two forms. In oneform, the toothed retainer is engaged and disengaged by movement towardand away from the jaws (“horizontal” movement). In the other form, thetoothed retainer is engaged and disengaged by movement generallyperpendicular to the jaws (“vertical” movement).

[0012] In another embodiment especially suited for use during aminimally invasive surgical procedure, a clamp having movable jaws isprovided with a slender, flexible, actuator that is not intended to beremoved during use. The actuator has a proximal end that defines ahandle and a distal end that is connected to the clamp. The jaws areactuated by axial movement of a screw that is connected to the end of acable included as part of the actuator. The screw passes through aslotted nut that permits non-rotational axial movement of the screw inone direction, but which requires that the screw be rotated in order tomove in the opposite direction. A stem having a knob is attached to theproximal end of the cable and extends outwardly from the handle.

[0013] When the knob is pushed inwardly (toward the handle), the stemand the cable are advanced, thereby axially moving the screw and closingthe jaws of the clamp. The nut prevents the jaws from being openedinadvertently. When is it necessary to remove the clamp, the knob isrotated. This causes the stem, cable, and screw to be rotated. When thescrew is rotated, it is moved axially relative to the nut and pulls thejaws to the open position.

[0014] The present invention provides an aorta cross clamp that can beused for cardiac surgery during either a gross thoracotomy or aminimally invasive procedure such as a percutaneous intercostalpenetration. With any embodiment of the invention, the clamp assembly iscompact, reliable, and easy to apply and remove. The foregoing and otherfeatures and advantages of the invention will be apparent from anexamination of the specification and claims that follow, including theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a perspective view of an aorta clamp assembly accordingto the invention especially adapted for use during a gross thoracotomyin which a clamp is disposed adjacent an actuator;

[0016]FIG. 2 is a top plan view of the clamp assembly of FIG. 1;

[0017]FIG. 3 is a side elevational view of the clamp assembly of FIG. 1;

[0018]FIG. 4 is a view similar to FIG. 1 showing an alternative aortaclamp assembly according to the invention especially adapted for useduring a gross thoracotomy;

[0019]FIG. 5 is a top plan view of the clamp assembly of FIG. 4;

[0020]FIG. 6 is a side elevational view of the clamp assembly of FIG. 4;

[0021]FIG. 7 is a perspective view of an aorta clamp assembly accordingto the invention especially adapted for use during minimally invasivecardiac surgery in which a clamp is mounted at the end of a flexibleactuator;

[0022]FIG. 8 is a view similar to FIG. 7 in which the components of theclamp assembly have been separated and spaced apart for purposes ofclarity of illustration; and

[0023]FIG. 9 is a enlarged plan view, partly in cross-section, of theproximal and distal ends of the actuator of FIG. 7.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0024] Referring to FIGS. 1-3, an aorta cross clamp assembly accordingto the invention is indicated by the reference numeral 10. The clampassembly 10 is especially adapted for use during a gross thoracotomy.The clamp assembly 10 includes a clamp 12 and an actuator 14. The clamp12 has a first jaw 16 a and a second jaw 18 a. A handle 16 b havingspaced sides is connected to the jaw 16 a. The handle 16 b includes aformation 16 c at its end. The formation 16 c has a slotted opening 16d. The second jaw 18 a is similar to the jaw 16 a. A handle 18 b isconnected to the jaw 18 a and includes a formation 18 c at its end. Aslotted opening 18 d is provided for the formation 18 c.

[0025] The handle 16 b is defined by a pair of spaced sides throughwhich the handle 18 b extends. The handles 16 b, 18 b are joined forpivotal movement by a hinge pin 20. Each of the jaws 16 a, 18 a isprovided with an elastomeric insert 22 that is intended to minimizetrauma to the aorta. The inserts 22 are attached to the respective jaws16 a, 18 a by fasteners 24. The longitudinal axes of the jaws 16 a, 18 aand the handles 16 b, 18 b are disposed relative to each other at anangle within the range of about 25-30 degrees, preferably about 27degrees, when viewed from the side (FIG. 3).

[0026] A curved rachet bar 26 is connected to the formation 16 c bymeans of a spring mounting 27. The ratchet bar 26 lies in the arc of acircle whose radius is approximately equal to the distance from thehinge pin 20 to the ends of the handles 16 b, 18 b. The mounting 27biases the rachet bar 26 toward the formations 16 c, 18 c. A pluralityof teeth 28 are provided on that portion of the rachet bar 26 whichfaces the formations 16 c, 18 c. A plurality of teeth 30 are provided onthe formation 18 c and face the teeth 28. The teeth 28, 30 are orientedsuch that they engage each other when the handles 16 b, 18 b areattempted to be moved apart, thereby preventing the handles 16 b, 18 bfrom being opened. In effect, the handle 18 b and the teeth 30 form apawl that permits closing movement of the jaws 16 a, 18 a, but whichprevents opening movement of the jaws 16 a, 18 a. When the handles 16 b,18 b (and hence, the jaws 16 a, 18 a) are closed, a small gap 32 (FIG.2) is formed between the handles 16 b, 18 b.

[0027] The actuator 14 includes first and second handles 34 a, 36 ahaving finger loops 34 b, 36 b at the proximal ends thereof. Arms 34 c,36 c are connected to and project from the handles 34 a, 36 a. A pair ofspaced discs 34 d, 36 d are disposed at the ends of the arms 34 c, 36 c.The discs 34 d, 36 d are spaced apart a distance slightly greater thanthe width of the formations 16 c, 18 c. The discs 34 d, 36 d are joinedby pins 34 e, 36 e. The pins 34 e, 36 e have a diameter slightly lessthan that of the slotted openings 16 d, 18 d.

[0028] The handles 34 a, 36 a are joined for pivotal movement by a hingepin indicated generally by the reference numeral 38. The actuator 14includes a third handle 40 a. The handle 40 a has a finger loop 40 b atthe proximal end thereof. The finger loop 40 b lies in a plane inclinedupwardly at an angle within the range of about 15-20 degrees, preferablyabout 17 degrees, from the plane in which the handle 40 a lies. An arm40 c is connected to and projects from the handle 40 a. A finger 40 dextends from the arm 40 c at a right angle to the longitudinal axis ofthe arm 40 c. The diameter of the finger 40 d is slightly less that thewidth of the space 32.

[0029] A sleeve 42 is disposed atop the hinge pin 38. The handle 40 aextends through the sleeve 42. An enlarged stop 40 f is mounted on thearm 40 c. A spring 40 g is fitted over the arm 40 c and engages thesleeve 42 and the stop 40 f. The spring 40 g biases the finger 40 d awayfrom the sleeve 42 (to the left as viewed in FIGS. 1-3).

Operation of the Clamp Assembly 10

[0030] When it is desired to use the clamp 12 to compress a patient'sascending aorta, the handles 34 a, 36 a are moved apart (to the dashedline position shown in FIG. 2) so that the pins 34 e, 36 e can beengaged with the slotted openings 16 d, 18 d, respectively. The finger40 d will be disposed in that space defined by the handles 16 b, 18 b,and the rachet bar 26. When the finger loops 34 b, 36 b are moved towardeach other (to the solid line position shown in FIG. 2), the handles 16b, 18 b will be moved toward each other, thereby closing the jaws 16 a,18 a. The jaws 16 a, 18 a will remain closed due to the interaction ofthe teeth 28, 30. The actuator 14 can be removed from the now-closedclamp 12 by moving the finger loops 34 b, 36 b slightly apart andthereafter pushing the actuator 14 slightly toward the clamp 12. Theactuator 14 then can be moved clear of the clamp 12 by spreading thefinger loops 34 b, 36 b apart.

[0031] When it is desired to remove the clamp 12, the foregoingprocedure is reversed so that the actuator 14 is reattached to the clamp12. If the surgeon's thumb and middle finger have been used tomanipulate the actuator 14, the surgeon can then place the index fingerin the finger loop 40 b and pull the finger loop 40 b to the right asviewed in FIGS. 1-3, against the bias exerted by the spring 40 g. Thefinger 40 d will engage the rachet bar 26, causing the teeth 28, 30 tobe disengaged. Thereafter, the finger loops 34 b, 34 c can be spreadapart in order to open the jaws 16 a, 18 a. The clamp assembly 10 thencan then be removed from the operative site.

A Second Embodiment

[0032] Referring now to FIGS. 4-6, an alternative aorta clamp assemblyespecially adapted for use during a gross thoracotomy is indicated bythe reference numeral 50. The clamp assembly 50 includes a clamp 52 andan actuator 54. The clamp 52 has a first jaw 56 a and a second jaw 58 a.A curved handle 56 b is connected to the first jaw 56 a. The handle 56 bincludes an upper, curved bar 56 c at its end and a lower, curved bar 56d that is parallel to, but spaced from, the upper bar 56 c. The secondjaw 58 a is similar to the arm 56 a. A handle 58 b is connected to thejaw 58 a and includes an upper, curved bar 58 c at its end and a lower,curved bar 58 d that is parallel to, but spaced from, the upper bar 58c.

[0033] A plurality of teeth 60 are provided on the lower bar 56 d, whilea plurality of teeth 62 are provided on the upper bar 58 c. The bars 56c, 58 d do not have any teeth. As can be seen in FIG. 4, the bars 56 c,56 d, 58 c, 58 d are fitted together so that the teeth 60, 62 engageeach other when the handles 56 b, 58 b are attempted to be moved apart,thereby preventing the handles 56 b, 58 b from being opened. In turn,the jaws 56 a, 58 a will be prevented from opening. The upper bar 56 cis spaced at a small distance from the bar 58 c, while the lower bar 56d is spaced a small distance from the bar 58 d.

[0034] The handles 56 b, 58 b are joined for pivotal movement by a hingepin 64. Each of the jaws 56 a, 58 a is provided with an elastomericinsert 66 that is intended to minimize trauma to the aorta. The inserts66 are attached to the respective jaws 56 a, 58 a by fasteners 67. Acurved spring 68 is disposed between the handles 56 b, 58 b and causesthe handles 56 b, 58 b to be biased apart. The longitudinal axes of thejaws 56 a, 58 a and the handles 56 b, 58 b are disposed relative to eachother at an angle within the range of about 25-30 degrees, preferablyabout 27 degrees, when viewed from the side (FIG. 6). When viewed fromabove (FIG. 5), the bars 56 c, 56 d, 58 c, 58 d lie in the arc of acircle whose radius is approximately equal to the distance from thehinge pin 64 to the ends of the handles 56 b, 58 b.

[0035] The actuator 54 includes first and second handles 70 a, 72 ahaving finger loops 70 b, 72 b at the proximal ends thereof. A pair ofopposed shells 70 c, 72 c are connected to the handles 70 a, 72 a,respectively. The shells 70 c, 72 c are of a size and shape to receivethe curved handles 56 b, 58 b, including the upper and lower curved bars56 c, 58 c, 56 c, 58 d. The handles 70 a, 72 a are joined for pivotalmovement by a hinge pin indicated generally by the reference numeral 74.When the handles 70 a, 72 a (and, hence, the shells 70 c, 72 c) areclosed, a small gap 75 (FIG. 5) is formed between the shells 70 c, 72 c.

[0036] The actuator 54 includes a third handle 76 a having a finger loop76 b at the proximal end thereof. The handle 76 a has a generallyogee-shaped distal end 76 c that includes an axially extending lowerportion 76 d. The lower portion 76 d is adapted to fit into the gap 75between the closed shells 70 c, 72 c and engage the lower curved bar 58d.

[0037] The actuator 54 includes a formation 78 which is connected to thehinge 74. A pair of spaced tabs 80 are included as part of the formation78. A hinge pin 82 extends through the tabs 80 and the handle 76 a. Aspring 84 is disposed intermediate the upper surface of the formation 78and the underside of the handle 76 a. The spring 84 biases the handle 76a away from the first and second handles 70 a, 72 a to that positionshown by the solid lines in FIG. 6.

Operation of the Clamp Assembly 50

[0038] When it desired to use the clamp 52 to compress a patient'sascending aorta, the shells 70 c, 72 c are disposed about the ends ofthe curved handles 56 b, 58 b in the open position. As the handles 70 a,72 a are moved toward each other, the jaws 56 a, 58 a will be moved tothe solid line position in FIG. 5. After the handles 70 a, 72 a havebeen moved apart and the shells 70 c, 72 c have been removed from thehandles 56 b, 58 b, the clamp 52 will remain in the closed positionshown by the solid lines in FIG. 5 due to the engagement between theopposed teeth 60, 62.

[0039] When it is desired to remove the clamp 52, the foregoingprocedure is reversed and the handle 76 a is pressed towards the handles70 a, 72 a. The lower portion 76 d will be pivoted into contact with thelower curved bar 58 d. Continued movement of the handle 76 a will causethe upper curved bar 56 d to engage the underside of the upper wallsthat define the shells 70 c, 72 c. Thereafter, continued movement of thehandle 76 a will cause the bars 58 c, 56 d to be moved relative to eachother such that the teeth 60, 62 become disengaged. Under the influenceof the spring 68, the handles 56 b, 58 b (and, hence, the jaws 56 a, 58a) will be moved apart as the handles 70 a, 72 a are moved apart fromeach other. After the jaws 56 a, 58 a have been moved enough to releasetheir grip on the aorta, the clamp 52 and the actuator 54 can beretracted from the operative site.

A Third Embodiment

[0040] Referring now to FIGS. 7-9, an aorta cross clamp assemblyespecially adapted for use during minimally invasive cardiac surgery isindicated generally by the reference numeral 90. The clamp assembly 90includes a clamp 92 and an actuator 94. The clamp 92 has a cylindricalbase 96 with a bore therethrough. A first jaw 98 is rigidly connected tothe cylindrical base. A second jaw 100 is pivotally connected to thecylindrical base 96. The connection is established by a slot 102 formedin the first jaw 98. A hinge pin 104 extends through the jaws 98, 100.Each of the jaws 98, 100 is provided with an elastomeric insert 106 thatis intended to minimize trauma to the aorta. The inserts 106 areattached to the respective jaws 98, 100 by fasteners 108.

[0041] A screw 110 is disposed within the bore. A screw 110 is aso-called quick advance screw having coarse, tapered threads. A slottednut 112 is connected to the cylindrical base 96 at that end opposite thejaws 98, 100. A link 114 is connected to the jaw 100. The connection isestablished by a slot 116 formed in the jaw 100 and a pin 118 that isconnected to the link 116 which extends through the slot 116. The link114 is rotatably connected to the screw 110. A drive connector 120having a plurality of longitudinally extending keyways is connected tothe other end of screw 110.

[0042] The actuator 94 includes a flexible housing 122. A fitting 124 isconnected to the proximal end of the housing 122. A cylindrical, hollowhandle 126 is connected to the fitting 124. A pair of finger loops 128extend from opposite sides of handle 126. A fitting 130 is connected tothe distal end of the housing 122. The fitting 124 is releasablyconnected to the handle 126, while the fitting 130 is releasablyconnected to the cylindrical base 96. Although the fittings 124, 130 canbe disconnected for purposes of cleaning and sterilization, it isexpected that they will remain connected as shown in FIG. 7 during thecourse of a surgical procedure.

[0043] An elongate flexible cable 132 extends through the housing 122. Acylindrical stem 134 is connected to the proximal end of the cable 132.A knurled knob 136 is disposed at the end of the stem 134. A splineddrive member 138 is connected to the distal end of the cable 132. Thesplines on the drive member 138 engage the keyways in the driveconnector 120 so as to establish a driving connection. As will beapparent from an examination of FIG. 9, the drive member 138 and theconnector 120 can be moved axially relative to each other.

Operation of the Clamp Assembly 90

[0044] Starting from the position shown FIG. 7, the clamp 92 can beactuated to cause the jaws 98, 100 to clamp an ascending aorta bypushing the stem 134 toward the handle 126 (from the full line positionin FIG. 9 to the dashed line position in FIG. 9). When the handle 126 ismoved in this manner, the cable 132 is moved within the housing so thataxial force is applied to the connector 120 and, hence, to the screw110. Due to the orientation of the screw threads relative to the nut112, the screw 110 will be moved axially, thereby causing the jaw 100 tobe pivoted toward the jaw 98. Although the screw 110 can be advancedtoward a jaw-closed position without rotation, it cannot be retractedwithout rotation for two reasons: (1) if the cable 132 is pulled out ofthe housing 122, the drive member 138 will be disconnected from thedrive connector 120, as shown in FIG. 9, and (2) the nut 112 will engagethe threads of the screw 110 so as to prevent retraction of the screw110.

[0045] When it is desired to loosen the jaws 98, 100 in order to removethe clamp 92 from the aorta, it is necessary to rotate the knob 136 sothat the stem 134, cable 132, drive member 138, connector 120, and screw110 all are rotated. When the screw 110 is rotated relative to the nut112, the screw 110 will be retracted from the bore in the base 96,thereby causing the jaw 100 to be pulled toward a jaw-open position.After sufficient movement of the jaw 100 has occurred, the clamp 92 canbe removed from the operative site.

[0046] It is possible for the various components of the invention to bemodified and still produce a satisfactory product. For example, andwithout limitation as to the type of changes that are within the scopeof the invention, the embodiment of FIGS. 1-3 could be provided as athird class lever similar to the embodiment of FIGS. 7-9, that is, thehandles 16 b, 18 b could be eliminated and the ratchet bar 26 and theformations 16 c, 18 c could be positioned between the hinge pin 20 andthe inserts 22. In this case, the ratchet bar 26 would be on the top orbottom of the jaws 16 a, 18 a or it would extend through an openingformed in one of the jaws 16 a, 18 a. The embodiments of FIGS. 4-6 couldbe reconfigured similarly. The embodiment of FIGS. 7-9 could be providedin the form of a first class lever by connecting a handle to the secondjaw 100, in a manner similar to the embodiments of FIGS. 1-3 and 4-6.

[0047] Although the invention has been described in its preferred formwith a certain degree of particularity, it will be understood that thepresent disclosure of the preferred embodiment has been made only by wayof example, and that various changes may be resorted to withoutdeparting from the true spirit and scope of the invention as hereinafterclaimed. It is intended that the patent shall cover, by suitableexpression in the appended claims, whatever degree of patentable noveltyexists in the invention disclosed.

What is claimed is:
 1. An aorta cross clamp assembly, comprising: aclamp having first and second jaws that are movable toward and away formeach other; a retainer operatively connected to the first and secondjaws and movable between locked and unlocked positions, the retainerwhen in the locked position permitting the jaws to move toward eachother but preventing the jaws from moving away from each other, and whenin the unlocked position permitting the jaws to move away from eachother; an actuator having first and second arms that are movable towardand away from each other, the arms being selectively and operativelyengageable with and disengageable from the first and second jaws; and athird arm selectively engageable with and disengageable from theretainer, the third arm being movable between a first position where thethird arm is disposed adjacent the retainer when the retainer is in thelocked position and a second position where the third arm engages theretainer and displaces it to the unlocked position.
 2. The assembly ofclaim 1 , wherein: the first jaw is connected to a first handle; thesecond jaw is connected to a second handle; a hinge pin connects thehandles for pivotal movement; the end of each handle remote from thehinge is configured to define a slotted opening; and the handles, whenin the jaw-locked position, have a space therebetween.
 3. The assemblyof claim 2 , wherein the retainer includes: a ratchet bar that isconnected at one end to a selected one of the handles and which includesa plurality of teeth on a surface facing the handles; and a plurality ofteeth on the other of the handles, the teeth on the handle adapted toengage the teeth on the ratchet bar.
 4. The assembly of claim 3 ,wherein: the ratchet bar is curved to a radius from the hinge pin thatapproximates the radius of the ends of the handles from the hinge pin;and the ratchet bar is spring-mounted to the selected handle with a biastoward contact with the end of the handle.
 5. The assembly of claim 3 ,wherein the actuator includes: a first arm connected to the firsthandle, the first handle having a finger loop; a second arm connected tothe second handle, the second handle having a finger loop; the first andsecond handles being connected to each other by a hinge; a third armconnected to a third handle, the third handle having a finger loop, thethird arm having a finger disposed at right angles to the third arm, thefinger being engageable with the ratchet bar.
 6. The assembly of claim 5, wherein: a sleeve is connected to the hinge, the third arm extendingthrough the sleeve; a stop is mounted on the third arm; and a spring isdisposed between the sleeve and the stop to bias the third arm to afinger-extended position.
 7. The assembly of claim 5 , wherein the endsof the first and second arms include space-apart discs that areconnected by a pin, the pin adapted to fit within one of the slottedopenings.
 8. The assembly of claim 1 , the first jaw is connected to afirst handle; the second jaw is connected to a second handle; a hingepin connects the handles for pivotal movement; and a spring is disposedbetween the handles and biases the handles apart.
 9. The assembly ofclaim 8 , wherein the retainer includes: a first ratchet bar that isconnected at one end to a selected one of the handles, the first ratchetbar including a plurality of teeth; a second ratchet bar that isconnected at one end to the other of the handles, the second ratchet barincluding a plurality of teeth; and the ratchet bars being disposedparallel to each other with the teeth on the respective ratchet barsfacing each other and engaging each other.
 10. The assembly of claim 9 ,further comprising: a first spacer bar disposed parallel to the firstratchet bar, the first spacer bar being connected to the end of theselected handle, the first spacer bar and the first ratchet bar beingspaced apart a distance sufficient for the second ratchet bar to bereceived therebetween; and a second spacer bar disposed parallel to thesecond ratchet bar, the second spacer bar being connected to the end ofthe handle to which the second ratchet bar is connected, the secondspacer bar and the second ratchet bar being spaced apart a distancesufficient for the first ratchet bar to be received therebetween. 11.The assembly of claim 10 , wherein the actuator includes: a first armconnected to the first handle, the first handle having a finger loop; asecond arm connected to the second handle, the second handle having afinger loop; the first and second handles being connected to each otherby a hinge; a third arm connected to a third handle, the third handlehaving a finger loop, the third arm being ogee-shaped and having anaxially extending lower portion, the axially extending lower portionbeing engageable with a selected one of the first or second spacer bars.12. The assembly of claim 11 , wherein: a formation is connected to thehinge, the formation having a pair of spaced tabs through which thethird arm extends; a second hinge pin extends through the third arm andthe tabs, the second hinge pin being disposed at right angles to thefirst hinge pin; and a spring is disposed between the formation and thethird arm to bias the third arm to position where the axially extendingposition is disposed adjacent a selected one of the first or secondspacer bars.
 13. The assembly of claim 11 , wherein: the ends of thefirst and second arms include shells adapted to receive the first andsecond handles of the clamp; the shells being movable toward each otherupon movement of the first and second handles of the actuator so as tomove the first and second handles of the clamp toward each other; andthe shells defining a space therebetween when the shells are closed, thespace being of a size and shape to permit the axially extending lowerportion of the third arm to pass therebetween.
 14. An aorta cross clampassembly, comprising: a clamp having first and second jaws that aremovable toward and away from each other; an elongate housing havingfirst and second ends, the clamp being connected to the first end; anelongate actuator disposed within the housing and operatively connectedto the jaws such that axial movement of the actuator within the housingcauses the jaws to move toward or away from each other; a retainerdisposed within the housing, the retainer having two modes of operation,the retainer in the first mode permitting the actuator to move withinthe housing such that the jaws are moved toward each other but not awayfrom each other, and the retainer in the second mode permitting theactuator to be moved within the housing such that the jaws are movedaway from each other; a handle connected to the second end of thehousing; and a stem connected to the actuator, the stem projectingoutwardly of the handle, the stem permitting the user to operate theactuator in either the first or second modes of operation permitted bythe retainer.
 15. The assembly of claim 14 , wherein the first jaw isfixed and the second jaw is movable toward or away from the first jaw.16. The assembly of claim 15 , wherein the clamp includes: a base havinga bore therethrough, the first jaw being connected to the base; a slotin the first jaw adjacent the connection with the base, the second jawbeing disposed within the slot; and a hinge pin extending through theslot and the second jaw to support the second jaw for pivotal movementwithin the slot.
 17. The assembly of claim 16 , wherein the retainerincludes: a screw disposed within the bore, the screw having first andsecond ends; a nut connected to the base, the screw passing through thenut, the connection between the nut and the screw being such that thescrew can move toward the second jaw without rotating but the screw canmove away from the second jaw only by being rotated; a slot in thesecond jaw; a link rotatably connected to the first end of the screw andconnected to the second jaw by a pin passing through the link and theslot; and a drive connector connected to the second end of the screw,the actuator being connected to the connector in driving relationship.18. The assembly of claim 15 , wherein the housing is flexible and theactuator is a cable.
 19. The assembly of claim 15 , wherein the secondend of the housing includes a fitting to which the handle is secured,the handle has a pair of finger loops, and the stem has a knob.